Cleaning compositions and method of using the same



United States Patent 3,410,804 CLEANING COMPOSITIONS AND- METHOD OF USING THE SAME Edward N. Walsh, Thornwood, N.Y., assignor to Stautfer Chemical Company, New York, N.Y., a corporation of Delaware No Drawing. Filed Jan. 3, 1966, Ser. No. 517,896 14 Claims. (Cl. 25299) ABSTRACT OF THE DISCLOSURE Cleaning compositions inhibited against attack on glass and glazed ceramic and porcelain surfaces comprising essentially between about 80% and 99% by weight of at least one ingredient selected from the group consisting of caustic alkali, alkali metal carbonate, alkali metal phosphate, alkali metal silicate, alkali metal borate, alkali metal sulfate, alkali metal chlorinated cyanurate, chlorinated cyanuric acid and chlorinated trisodium phosphate, and between about 0.5% and 20% by weight of at least one alkali metal aluminum orthophosphate.

The present invention is directed to improved cleaning compositions inhibited against deteriorative attack upon glass and glazed ceramic and porcelain surfaces, and a method of cleaning said glass and glazed ceramic and porcelain surfaces using said cleaning compositions in aqueous media.

Those skilled in this art have heretofore been aware that the strong alkaline solutions, such as those containing free caustic alkali, used industrially in washing bottles and other glassware will etch or frost the surface of the glass and palpably diminish its pleasing appearance. Less alkaline cleaning solutions (pH 8-13) used predominantly in household automatic dishwashing machines have also been known to attack and etch glazed or glass surfaces, in some instances removing completely the pattern from glazed chinaware or earthenware. A variety of inhibitor additives have been suggested to prevent alkaline attack, see for example, U.S. Patent Nos. 2,241,984, 2,419,805, 2,447,297, and 2,575,576. These prior are inhibitors are mainly water-soluble zinc, beryllium and aluminum compounds. Although they are effective to some extent, none has been entirely satisfactory in completely preventing the attack on glass or glazed surfaces.

One object of this invention is to provide alkaline cleaning compositions having improved inhibition against attack on glass or glazed ceramic or porcelain surfaces.

Another object is to provide a group of inorganic phosphorous compounds which inhibit to a very substantial degree the attack of automatic dishwasher detergent compositions and the like upon glazed china and earthenware.

Other objects will become apparent as the description expands.

I have now discovered that the alkaline and acidic alkali metal aluminum orthophosphates may be incorporated in alkaline cleaning compositions to substantially reduce attack on glass and glazed surfaces. An unexpected and important finding is that the alkali metal aluminum orthophosphates are markedly superior for this purpose to sodium aluminate, the standard inhibitor used today in household detergent dishwashing compositions.

The acidic orthophosphate inhibitors of the instant invention may be represented by the following empirical formula:

wherein M is an alkali metal, preferably sodium and/or potassium, x is an integer between 1 and inclusive, y is an integer between 2 and 4 inclusive, and z is an integer between 11 and 17 inclusive, with the sum of x+3y+z 3,410,804 Patented Nov. 12, 1968 ice numerically equal to the sum of the valences of the phosphate (PO 5) radicals, i.e., between 21 and 30. The sodium aluminum acid orthophosphates known heretofore to be useful principally as leavening acids and as additives in other food compositions represent a preferred group of compounds b the present invention. These compounds and their methods of preparation are set forth in the following U.S. patents and patent applications; U.S. 3,223,- 480, 3,223,479, 3,205,073, 2,995,421, 2,957,750, 2,550,- 490, and U.S. Ser. No. 173,054 now abandoned. Some specific acidic compounds especially preferred for use in accordance with the present invention have the following formulas:

NaA13H14(PO4) -4H2O s 2 15( 4)s Na Al H (PO,) .2.5H O

The alkaline orthophosphates which may be used in accordance with the present invention and their method of preparation are set forth in U.S. Patent 3,097,949, issued July 16, 1963. The alkaline sodium aluminum orthophosphate reaction products have the following approximate empirical composition:

wherein x is a number of from 6 to 15, y is a number from 1.5 to 4.5, and z is a number from 4 to 40. As used hereinafter and in the appended claims, the expression alkali metal aluminum orthophosphates or sodium aluminum orthophosphates is intended to include both the acidic and alkaline orthophosphates described hereinabove.

The cleaning compositions of the instant invention are mixtures which may comprise, in addition to the inhibitors disclosed herein, a multiplicity of various well known ingredients but normally between about and 99% by weight of one or more of the following: a caustic alkali such as sodium hydroxide; an alkali metal salt such as alkali metal carbonates, phosphates, borates, silicates and sulfates; an organic or inorgnic active chlorine compound such as an alkali metal chlorinated cyanurate, chlorinated cyanuric acid, chlorinated trisodium phosphate or other nitrogen-containing halogenated compound, e.g., N-chloro succinarnide; and possibly a detergent or surface active compound, preferably a low or non-foamer, e.g., a nonionic alkyl aryl polyether such as Triton CF 10, a nonionic amine polyglycol condensate such as Triton CF 32, or an anionic sodium dodecyl diphenylether disulfonate such as Benox 2A1. Alternatively a moderate or high foaming detergent may be used together with a foam depressant such as a silicone anti-foam compound. A germicidal quaternary ammonium compound, such as benzenethionium chloride is also commonly used in such cleaning compositions. In preparing for a cleaning operation, these compositions are dissolved in water maintained at a suitable temperature (usually above 120 F.), the proportions of cleaning composition and water being such that the cleaning solutions formed are suitable for the intended industrial or household use.

For industrial bottle cleaning operations, the cleaning composition is of the highly alkaline type (pH 12 or above) consisting normally of about 50% to by weight of caustic alkali (sodium hydroxide), 0% to 40% by weight of one or more materials selected from sodium carbonate, trisodium phosphate, tetrasodium pyrophosphate and sodium metasilicate, and 0.5 to 20% by weight of an etching inhibitor as described hereinbefore.

The household dishwashing detergent compositions will comprise normally between about 20% and 80% of a condensed phosphate builder (sodium tripolyphosphate, tetrasodium pyrophosphate, potassium pyrophosphate, etc.), and between 5% and 65% by weight of one or more of the following: a sodium silicate (e.g., sodium metasilicate anhydrous or pentahydrate), preferably a detergent or surface active agent, and one or more specialized ingredients or fillers such as sodium chloride trisodium phosphate, sodium borate, chlorinated trisodium phosphate, chlorinated cyanuric acid derivatives, sodium sulfate, sodium carbonate, and a sanitizing agent. An organic water softening or chelating ingredient such as the salts of ethylenediamine tetracetic acid or nitrilo acetic acid and the like may also be used in place of part or all of the phosphate builder.

Both the household and industrial cleaning compositions may be dissolved, preferably in water, and marketed in solution suspension or emulsion form to be later dissolved in a large volume of water for practical use. Accordingly, proportions given are on a dry weight basis and do not include any water or other solvent which may be used to convert the cleaning compositions to a liquid form. However, the usual practice is to prepare and market such compositions in powdered or granular form.

A household dishwasher detergent may also contain borax (sodium tetraborate) and common salt (sodium chloride). Industrial cleaning compositions may in addition to the aforesaid ingredients contain sodium gluconate, sodium citrate or sodium tartrate.

The alkali metal aluminum orthophosphates are effective in preventing attack at concentrations as low as about 0.5% and as high as 20% by weight of the dry ingredients. A preferred concentration in the dry industrial bottle washing formulations is between 2% and 15% by weight. In household dishwashing formulations a particularly preferred range for the inhibitor is between 2% and 6% by weight.

Typical dishwashing compositions in accordance with the invention will preferably contain the following ingredients in the indicated proportions Ingredient: Parts by Weight Sodium tripolyphosphate 3060 Trisodium phosphate 30 Sodium metasilicate -50 Sodium carbonate 0-20 Detergent 0-4 Alkali metal aluminum orthophosphate 26 In the above formulation, the trisodium phosphate may be chlorinated.

A typical dishwashing formulation according to this invention containing a chlorinated isocyanurate has the following ingredients Ingredient: Parts by weight Sodium tripolyphosphate 40 Trisodium phosphate 10 Sodium metasilicate, anhydrous 35 Sodium carbonate 9 Surfactant (Triton CF-lO) 1 Potassium dichloroisocyanurate 1 Alkali metal aluminum orthophosphate 4 TABLE I.TEST FORMULATION Ingredient: Parts by Weight Sodium tripolyphosphate 40 Trisodium phosphate 10 Sodium metasilicate, anhydrous 35 Sodium carbonate 10 Surfactant (Triton CF-10) 1 Inhibitor 4 RESULTS Retardation of China Glaze Attack [10-hour immersion time: 212i1 F.]

1 Visual observation of china pattern and glaze after 10 hours. Scale of 1 through 10: 10 indicating relative maximum deterioration; 1 indicating minimum deterioration.

In the above table, the compound having the formula Na Al I-I (PO -2.5H O and its method of preparation are not previously disclosed in the art. This compound may be prepared as follows: To 10 moles of H PO acid) is added 1.35 moles of Na CO and the mixture is heated to 80 C. Then 1.15 moles of Al O -3H O is added and the mixture heated to C. The reaction mixture is held under reflux at 90 C. until considerable precipitate forms. The mixture is subsequently filtered; the collected sodium aluminum phosphate crystals are washed with cold water, then ethanol and finally dried at C. By elemental analysis, the compound corresponds to the formula Na Al H (PO -2.5H O with an X-ray diffraction pattern showing lines of major intensity at 3.07, 4.00 and 8.10 angstroms. It is soluble to the extent of 4 g. per 100 ml. H O with some decomposition and exhibits a pH of 3.0 in a 1% solution. The absolute density is 2.47 g. per cc.; indices of refraction N =L518 and 1.564. Upon differential thermal analysis the compound exhibits endotherms at 210 C. (about 6 moles of H 0 loss), 240-255 C. (an additional 1.5 moles H O loss), 320 C. (an additional 1.5 moles H O loss) and 430 C. (an additional 1 mole H O loss). The crystals by microscopic examination appear to be rhombohedral with oblique extinction under cross-Nichols.

The following examples will serve to further illustrate the instant invention but should not be construed as limiting the same.

Example 1 Dishwashing detergent compositions were formulated and tested in accordance with the CSMA standard procedure mentioned supra.

40 g. of sodium tripolyphosphate, 35 g. of anhydrous sodium metasilicate, 10 g. of trisodium phosphate, and 10 g. of sodium carbonate were placed in a wide-mouth beaker and mixed with a spatula. One cc. of Triton CF-10 surfactant was added dropwise from a Wide-mouth pipette with mixing of the dry ingredients. A 4 g. portion of the inhibitor compound was then added to the dry ingredients with mixing. A part of this mixture was then dissolved in distilled water, the proportions being such as to yield a solution containing 0.3% by weight of the mixture. The solution was heated to its boiling point and maintained in a boiling condition thereafter. Small glazed saucers having a colored pattern thereon were immersed in the boiling solution for a period of ten hours. During this ten-hour test, the plates were removed from the boiling solution at 1 hour intervals, dried with soft white paper tissues and examined visually for changes in pattern intensity and glaze removal. Instrumental evaluation of pattern and glaze changes was accomplished with a Hunter Glossometer (Model D36) which gave values correlating substantially with visual observations. The results are summarized hereafter.

5 China Glaze Attack [10 hour immersion: 2l2i1 F.]

(a) Inhibitor: Sodium alu-minate (standard) [Solution pH: Initial12.5, final-12.02] Time (brs.): Observations Bright glosspattern intense.

l Do.

Several faint water marks 1 appear. 6 Do.

10 When compared with an untreated saucer,

the coloration of the treated one appears only slightly fainter. Some water marks are present.

As used herein water marks refers to very fine lines which appear in the glazed dish surface. Since these lines are produced by attack of the glaze by alkali, they cannot be removed by washing, rubbing or ordinary after-treatment of the dishes.

(b) Inhibitor: NaAl H (PO -4H O [Solution pH: Initial-12.3, Final10.9] Time (brs.): Observations 0 Bright gloss.pattern intense.

I Do.

9 Water marks appear.

10 When compared with an untreated saucer, the treated one appears not to have failed in coloration. Some Water marks are apparent.

(c) Inhibitor: Na Al H (PO [Solution pH: Initiall2.4, Final-12.05] Time (brs.): Observations 0 Bright gloss-pattern intense.

I Do.

2 Faint blemishes appear but fade until 7 Blemishes no longer present.

10 Treated saucer showed no water marks or fading when compared to untreated saucer.

Inhibitor: N33A13H15(P04)9-2.5H20 [Solution pH: Initiall2.30, Finalll.75]

Time (hrs.): Observations v 0 Bright gloss--pattern intense.

I Do.

2 Some very faint water-marks appear.

10 Saucer shows no loss of gloss or coloration and has only faint water marks.

(e) Inhibitor: none (control) [Solution pH: Initial-l2.45, Finall1.8] Time (brs.): Observations Using the same procedure set forth in Example 1 but with a chlorine-containing dishwashing formulation, various sodium aluminum phosphates were tested for their elfect in preventing the attack on glazed china surfaces. The following formulation was employed:

Formulation Ingredient: Parts by weight Sodium tripolyphosphate 45 Sodium metasilicate pentahydrate 20 Sodium carbonate 10 Chlorinated trisodium phosphate 20 Surfactant (Triton CF-lO) l Inhibitor 4 The results of these tests are summarized in the following data:

China Glaze Attack [10 hour immersion: 212- L1 F.]

(a) Inhibitor: Sodium Aluminates [Solution pH: Initial11.8, Final1l.0]

Time (brs.): Observations 0 Bright glosspattern intense.

I Do.

5 Faint water marks appear; gold trim dull. 6 Do.

8 More water marks appear.

10 Gold trim dull. Some faint water marks present. No fading of pattern color or loss of gloss.

Inhibitor: 15Na O 2.8Al203 8P205 'XHQO [Solution pH: Initial10.8, Final-10.95]

Time (brs.): Observations 0 Bright glosspattern intense.

6 Blemishes appear all over.

7 Most blemishes fade.

9 Red and pink portions appear pinpricked.

10 Paint water marks on bottom. Red and pink portions of saucer appear pin-pricked.

(c) Inhibitor: NaAI H (PO -4H O [Solution pH: Initial10.9, Final10.8]

Time (hrs): Observations Bright gloss-pattern intense.

I Do.

2 Gold trim more orange; faint water marks appear.

7 Dark red fading; underside is dull.

10 Paint water marks on underside; dark red has faded. Gold trim slightly more orange; no loss of gloss.

(d) Inhibitor: none (control) [Solution pH: Initiall2.00, Fin al10.65

Time (hrs): Observations considerably; gloss only slightly duller.

Qualitatively, the observations set forth above indicated that with the chlorinated TSP formulation, the alkaline sodium aluminum phosphate gave the most prolonged initial protection (hours of protection: b w c d), while the acidic sodium aluminum phosphate gave the highest degree of over-all protection for 10 hours (degree of protection: c a bd).

Example 3 An industrial bottle washing solution is prepared by dissolving 48 parts caustic soda and 7 parts inhibitor in 1,450 parts by weight of water. Into this solution, maintained at a temperature of 185i5 F., are placed new glass bottles weighing approximately 400 g. After exposing the bottles to this solution for a period of six days, the bottles are removed from the solution and weighed to determine the weight loss after exposure. By the above procedure, the acidic and alkaline sodium aluminum phosphates are found to inhibit attack on the glass bottles to a substantial degree.

What I claim is:

1. A cleaning composition inhibited against attack on glass and glazed ceramic and porcelain surfaces consisting essentially of between about 80% and 99% by weight of at least one ingredient selected from the group consisting of caustic alkali, alkali metal carbonate, alkali metal phosphate, alkali metal silicate, alkali metal borate, alkali metal sulfate, alkali metal chlorinated cyanurate, chlorinated cyanuric acid, and chlorinated trisodium phosphate, and between about 0.5% and by weight of at least one alkali metal aluminum orthophosphate of the formulae:

M A1 H (PO4) 7 m wherein M is an alkali metal, x is an integer between 1 and 5 inclusive, y is an integer between 2 and 4 inclusive, and z is an integer between 11 and 17 inclusive, with the sum of x+3y+z numerically equal to the sum of the valences of the phosphate (PO radicals; and

wherein x is a number of from 6 to 15, y is a number from 1.5 to 4.5, and z is a number from 4 to 40.

2. The cleaning composition of claim 1 wherein said composition consists essentially of between 50% and 95% by weight of caustic alkali and between 2% and 15% by weight of at least one sodium aluminum orthophosphate.

3. An alkaline water soluble organic anionic or nonionic automatic dishwashing composition inhibited against attack on glass and glazed ceramic and porcelain surfaces consisting essentially of between 20% and by weight of a condensed phosphate builder; and between 0.5% and 20% by weight of at least one sodium aluminum orthophosphate of the formulae:

wherein M is an alkali metal, x is an integer between 1 and 5 inclusive, y is an integer between 2 and 4 inclusive, and z is an integer between 11 and 17 inclusive, with the sum of x+3 y+z numerically equal to the sum of the valenecs of the phosphate (PO radicals; and

wherein x is a number of from 6 to 15, y is a number from 1.5 to 4.5, and z is a number from 4 to 40.

4. The alkaline dishwashing composition of claim 3 wherein said composition consists essentially of the following ingredients in the indicated proportions- Ingredient: Parts by weight Sodium tripolyphosphate 30-60 Trisodium phosphate 5-30 Sodium metasilicate 10-50 Sodium carbonate 0-20 Alkali metal aluminum orthophosphate 2-6 5. The alkaline dishwashing composition of claim 3 wherein said composition comprises essentially the following ingredients in the approximate indicated proportions- Ingredient: Parts by weight Sodium tripolyphosphate 40 Trisodium phosphate 10 Sodium metasilicate, anhydrous 35 Sodium carbonate 10 Sodium aluminum orthophosphate 4 6. The alkaline dishwashing composition of claim 3 wherein said composition comprises essentially the following ingredients in the approximate indicated proportions- Ingredient: Parts by weight Sodium tripolyphosphate 45 Sodium metasilicate 20 Sodium carbonate 10 Chlorinated trisodium phosphate 20 Sodium aluminum orthophosphate 4 7. The alkaline dishwashing composition of claim 3 wherein said composition comprises essentially the following ingredients in the approximate indicated proportions Ingredient: Parts by weight Sodium tripolyphosphate 40 Trisodium phosphate 10 Sodium metasilicate, anhydrous 35 Sodium carbonate 10 NaAl H (PO -4H O 4 8. The alkaline dishwashing composition of claim 3 wherein said composition comprises essentially the following ingredients in the approximate indicated proportions- Ingredient: Parts by weight Sodium tripolyphosphate 40 Trisodium phosphate 10 Sodium metasilicate, anhydrous 35 Sodium carbonate 10 Na A13H15(PO )92.5H O 4 9. The alkaline dishwashing composition of claim 3 wherein said composition comprises essentially the following ingredients in the approximate indicated proportions Ingredient: Parts by weight Sodium tripolyphosphate 40 Trisodium phosphate 10 Sodium metasilicate, anhydrous 35 Sodium carbonate 10 Na Al2H15(PO4) 4 10. The alkaline dishwashing composition of claim 3 wherein said composition comprises essentially the following ingredients in the approximate indicated proportions Ingredient: Parts by weight Sodium tripolyphosphate 45 Sodium metasilicate, pentahydrate 20 Sodium carbonate 10 Chlorinated trisodium phosphate 20 11. The alkaline dishwashing composition of claim 3 wherein said composition comprises essentially the following ingredients in the approximate indicated proportions- Ingredient: Parts by weight Sodium tripolyphosphate 45 Sodium metasilicate, pentahydrate 20 Sodium carbonate 10 Chlorinated trisodium phosphate 2O Na3A12H15(PO4)g.4H2O 4 12. The alkaline dishwashing composition of claim 3 wherein said composition comprises essentially the following ingredients in the approximate indicated proportions Ingredient: Parts by weight Sodium tripolyphosphate Trisodium phosphate 10 Sodium metasilicate 35 Sodium carbonate 9 Potassium dichloroisocyanurate 1 Sodium aluminum orthophosphate 4 13. A method for inhibiting the attack by an aqueous alkaline cleaning solution on glass and glazed ceramic and porcelain surfaces which comprises dissolving in said aqueous alkaline solution between 0.5% and 20% by dry weight of the cleaning ingredients therein of an alkali metal aluminum orthophosphate drying the glass, glazed ceramic and porcelain surfaces.

14. The method of claim 13 wherein the aqueous alkaline cleaning solution is suitable for use in an automatic dishwashing operation, the alkali metal aluminum orthophosphate is sodium aluminum orthophosphate, and the latter is present in an amount which comprises between 2% and 6% by dry weight of the ingredients in said aqueous alkaline cleaning solution.

References Cited UNITED STATES PATENTS 2,241,984 5/1941 Cooper 252-156 2,419,805 4/1947 Wegst et a1. 252156 2,447,297 8/1948 Wegst et a1. 252 2,575,576 11/1951 Bacon et a1. 252138 3,097,949 7/1963 Lauck et al 23105 XR 3,128,250 4/ 1964 Lintner 25699 MAYER WEINBLATT, Primary Examiner. 

